1. Field of the Invention
The present invention pertains to anchoring means for anchoring apparatus such as a well packer in a predetermined position within a well conduit or the like, said means including a plurality of bidirectional one piece slip members which are set in the anchoring position by improved mechanism.
2. Description of the Prior Art
In the art of downhole well apparatus and other devices which are adapted to be anchored within an elongated circuit, a number of mechanisms have been developed to provide for releasably anchoring the apparatus by means of radially extendable gripping elements sometimes referred to as slips. In particular, in the art of well packers and other well devices, there are a number of arrangements which have been devised which are characterized by the provision of slip members comprising toothed segments which coact with axially movable wedge members or cones to be radially extended and retracted with respect to the longitudinal axis of the apparatus for releasably gripping the inner wall of the conduit to anchor the apparatus in a predetermined position.
One widely used design of an anchoring mechanism for well packers is characterized by sets of upper and lower unidirectional slip members which are provided with tenon or heel portions engageable with an intermediate slip ring and wherein each set of unidirectional slips is engageable with respective upper and lower wedge or cone members. The proper setting of opposed unidirectional slips can be a problem in the art of well packers and the like in that the setting mechanism does not always function to set both sets of slips with equal gripping force on the well conduit. Under such circumstances the entire axial load on the packer, as a result of fluid pressure in the well and/or the weight of tubing connected to the packer, may be imposed on only one set of slips thereby causing mechanical failure of the slips or movement of the packer from its desired position in the well.
In order to simplify the anchoring mechanism for well apparatus such as packers and the like, single piece bidirectional slips have been developed. However, most known types of single piece bidirectional slips are provided with troublesome spring type retraction members for biasing the slips into the retracted position when the cone or wedge members are moved away from each other to relieve the radial outward displacement of the slips. Moreover, known types of single piece bidirectional slip members are not adapted to be set at one end and then at the other end so that a longitudinal compressive load is placed on the slip members and a complete setting operation is assured for both ends of the slip members.
The present invention is directed to an anchoring mechanism for a well apparatus or the like including a plurality of one piece bidirectional anchoring members or slips, which mechanism overcomes many of the disadvantages of known types of slip systems and which is more economical to manufacture in conjunction with various types of downhole well apparatus adapted to be anchored within a well conduit.